我常把莉莉当做露西(翻译)

I always mistake Lily for Lucy.

(mistake A for B: to think wrongly that sb/sth is sb/sth else)

I ofen make Lili as Lucy.

纠正楼上，“错当成”应该是take A for B,不是“make”。莉莉的名字也不对。

我常把莉莉当做露西(翻译)

I ofen take Lily for Lucy.